Conventionally, blood sample processing apparatuses have been known in which an aspiration tube penetrates a lid (cap) for sealing a specimen container to aspirate the blood sample in the specimen container and the aspirated blood sample is processed.
Among such blood sample processing apparatuses, there is an apparatus which repeatedly performs an inclining-stirring operation, in which a specimen container held in an upright state is rotated to be in an inclining state such that a bottom portion of the specimen container is positioned higher than a lid, and then is returned to its original upright state, and then which aspirates a blood sample to carry out analysis.
For example, a sample analysis apparatus described in U.S. Patent Publication No. 2007/110627 is provided with a hand member for holding a specimen container and a driver for rotating the hand member, and performs an inclining-stirring operation of the specimen container by rotating the hand member holding the specimen container before aspirating a blood sample from the specimen container by an aspiration tube.
The pressure inside the specimen container is higher than the pressure of the atmosphere, therefore, in the blood sample processing apparatus which performs such an inclining-stirring operation, the blood sample may be aspirated after opening the inside of the specimen container to the atmosphere in order to secure the quantitative precision in aspirating a blood sample by the aspiration tube.
The opening to the atmosphere is performed by various methods, and for example, there is an apparatus which uses an aspiration tube having a groove extending in a longitudinal direction in an outer circumferential surface thereof to open the inside of a specimen container to the atmosphere before aspirating a blood sample by the aspiration tube. In such an apparatus, when the aspiration tube penetrates the lid of the specimen container, the inside of the specimen container is opened to the air via the groove and thus the inside of the specimen container can be opened to the atmosphere.
However, when performing an inclining-stirring operation of a specimen container as in the sample analysis apparatus described in U.S. Patent Publication No. 2007/110627, a blood sample may adhere to the back side of the lid of the specimen container in accordance with the lid type. The pressure in the sealed specimen container is higher than the pressure of the atmosphere as described above. Accordingly, when an aspiration tube having a groove extending in a longitudinal direction in an outer circumferential surface thereof penetrates the lid of the specimen container in a state in which the blood sample adheres to the back side of the lid, the blood sample adhering to the back side of the lid may leak from the upper surface of the lid through the groove of the aspiration tube.